不同光照强度的紫外光对几种水生植物的过氧化氢酶（CAT）活性的影响

试验通过测定在不同光照强度的紫外光（ＵＶ）照射后，三种植物的过氧化氨酶（ＣＡＴ）分解过氧化氢后放出氧气量（体积），确定植物的ＣＡＴ活性。试验结果表明：三种植物（浮萍，水花生，菱）的ＣＡＴ对不同光照强度的ＵＶ均有明显的生态效应，但其效应表现随物种而异。浮萍对Ｕｙ最敏感，其ＣＡＴ活性的峰值（１．５２）出现在较低光照强度（１４８．８１ｘ），其次是水花生，其ＯＡＴ活性的峰值（１．３８）出现在较高光照强度（２２３．２１ｘ），菱对ＵＶ的效应与浮萍和水花生的效应相反，表现为ＣＡＴ活性被抑制（低于对照组样品的ＣＡＴ活性值）．三种植物在效应上的差异是与植物种的污染生态学特性的不同有关。

THE EFFECTS OF DIFFERENT LIGHT INTENSITY OF UV ON THE CATALASE (CAT) ACTIVITIES OF SEVERAL SPECIES OF AQUATIC PLANTS

By measuring the volume of O2 which is released after the CAT of thePlants exposed to different light intensity of UV decomposes H2O2, the CATactivities of the exposed plants are determined.The results show that there aresignificant effects of the different light intensity of UV on the OAT activities ofthe three plants, Lemna minor, Alternanthera Philoxeroides and Trapa bocornis.It is due to their different ecological characteristics. Lemna minor, a resistantPlant, is much more sensitive to the UV light than Alternanthera philoxeroides.There is the maximum volume of CArd aetivity (1. 52) for Lemna minor whenexposed to lower light intensity of UV (148.81x) .There is the maximum volume ofCAT activity (1. 38) for Alternanthera philoxeroides when exposed to higher lightintensity of UV (223. 2 1x). In contrast, the volume of the CAT activity of Trapabicornis is below the control test group's. The above-mentioned indieates thestimulating effectS of UV light on pollution resistant plaaes, Lemna donor andAlternanthera Philoxeroides, as well as the inhibiting effects of UV light on theOAT aotittiy of the senSitive plant, Thapa bioornis.